Decolorization of Post-Consumer Fibers

ABSTRACT

Methods, compositions, single phase aqueous solutions, process mixtures, and kits are provided relating to decolorizing post-consumer fibers, e.g., from carpet pile, using a single-phase aqueous solution. For example, a method of decolorizing post-consumer fibers may include providing the single phase aqueous solution. The single phase aqueous solution may include water, a stable peroxygen composition, and a surfactant composition. The method may include providing the post-consumer fibers comprising a colorant. The method may include contacting the single phase aqueous solution and the post-consumer fibers to form a process mixture under conditions effective to provide a decolorized portion of the post-consumer fibers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 62/452,504, filed on Jan. 31, 2017, which is incorporated by reference herein in its entirety.

BACKGROUND

Use and replacement of fibers such as those in carpeting generates nearly 4 billion pounds of post-consumer waste added to landfills annually. The large and increasing volumes of such waste is a significant industrial and environmental concern. However, major obstacles prevent achieving economical recycling of post-consumer fibers. For example, polymeric fibers, such as carpet fibers, may include undesirable colorants. For example, colorants may include dyes, pigments, inks, colored contaminants or recycling byproducts, and the like, which may be bound or embedded or otherwise difficult to remove from such post-consumer fibers. It is desirable to process polymeric fibers to remove undesired colorants prior to further uses of the fibers, such as recycled feedstocks for remanufactured carpeting.

The present application appreciates that removing colorants from post-consumer fibers may be a challenging endeavor.

SUMMARY

In one embodiment, a single-phase aqueous solution for at least partly decolorizing post-consumer fiber is provided. The single-phase aqueous solution may include water; a stable peroxygen composition; and a surfactant composition. The surfactant composition may include at least one of: a polyethylene glycol alkylphenol ether and a water-soluble polymer. The water-soluble polymer may include repeat units corresponding to monomers of one or more of: acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole.

In another embodiment, a process mixture is provided. The process mixture may include a post-consumer fiber. The post-consumer fiber may include a colorant. The process mixture may include a single-phase aqueous solution in contact with the post-consumer fiber. The single-phase aqueous solution may include water; a stable peroxygen composition; and a surfactant composition. The surfactant composition may include at least one of: a polyethylene glycol alkylphenol ether and a water-soluble polymer. The water-soluble polymer may include repeat units corresponding to monomers of one or more of: acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole.

In one embodiment, a method for at least partly decolorizing post-consumer fiber using a single-phase aqueous solution is provided. The method may include providing the single phase aqueous solution. The single-phase aqueous solution may include water; a stable peroxygen composition; and a surfactant composition. The surfactant composition may include at least one of: a polyethylene glycol alkylphenol ether and a water-soluble polymer. The water-soluble polymer may include repeat units corresponding to monomers of one or more of: acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole. The method may include providing the post-consumer fiber. The post-consumer fiber may include one or more colorants. The method may include contacting the single phase aqueous solution and the post-consumer fiber to form a process mixture under conditions effective to provide a decolorized portion of the post-consumer fiber.

In another embodiment, a kit for decolorizing post-consumer fiber is provided. The kit may include a stable peroxygen composition. The kit may include a surfactant composition. The surfactant composition may include at least one of: a polyethylene glycol alkylphenol ether; and a water-soluble polymer. The water-soluble polymer may include repeat units corresponding to monomers of one or more of acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole. The kit may include instructions. The instructions may direct a user to provide the stable peroxygen composition and the surfactant composition as a single-phase aqueous solution. The instructions may direct a user to contact the single phase aqueous solution and to a post-consumer fiber comprising a colorant to form a process mixture under conditions effective to provide a decolorized portion of the post-consumer fiber.

In one embodiment, a decolorized post-consumer fiber is provided.

DETAILED DESCRIPTION

The present application relates to compositions, process mixtures, methods, and kits for decolorizing post-consumer fibers, e.g., fibers derived from a carpet, a rug, an upholstery, a vehicle interior, a drapery material, an article of clothing, and the like.

In various embodiments, a single-phase aqueous solution for at least partly decolorizing post-consumer fiber is provided. The single-phase aqueous solution may include water; a stable peroxygen composition, and a surfactant composition. The surfactant composition may include at least one of: a polyethylene glycol alkylphenol ether and a water-soluble polymer. The water-soluble polymer may include repeat units corresponding to monomers of one or more of acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole.

In some embodiments, the stable peroxygen composition may include an alkali metal salt of one or more of: peroxide, percarbonate, persulfate, or perborate. The alkali metal may include a cation of, for example, lithium, sodium, potassium, and the like. For example, the stable peroxygen composition may include sodium percarbonate. The stable peroxygen composition may be present in an amount effective to provide a peroxide concentration in millimoles per liter (mM) of about one of: 10, 20, 25, 50, 75, 100, 125, 150, 175, 191, 200, 225, 250, 275, 300, 350, 400, 450, 500, 600, 700, 800, 900, or 1000. e.g., about 191 mM, or a range between any two of the preceding values, e.g., between about 10-1000 mM, 20-500 mM, 50-400 mM, and the like. The stable peroxygen composition may include sodium percarbonate in a weight percent concentration (w/w) with respect to the water of about one of: 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.75%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, e.g., 1%, or a range between any two of the preceding values, e.g., 0.05%-5%, 0.1%-5%, and the like.

In several embodiments, the surfactant composition may include the polyethylene glycol alkylphenol ether. The single-phase aqueous solution may include the polyethylene glycol alkylphenol ether in a weight percent concentration (w/w) with respect to the water of about one of: 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.25%, 0.3%, 0.35, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4, 4.5%, or 5%, e.g., 0.1%, or a range between any two of the preceding values, e.g., 0.01%-5%, and the like. The polyethylene glycol alkylphenol ether may be characterized by an average number of ethylene oxide repeat units of one of about: 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, e.g., 10 or 12, or a range between any two of the preceding values. e.g., 7-25, 8-14, and the like. The alkyl group of the polyethylene glycol alkylphenol ether may be a C₄-C₁₆, branched or unbranched alkyl group, e.g., butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, 1, 1, 3, 3, tetramethyl butyl, and the like. The polyethylene glycol alkylphenol ether may be represented by the following formula, wherein n is an average number of repeat units from about 9 to about 14:

In some embodiments, the polyethylene glycol alkylphenol ether may include, for example, one or more of: octoxynol-9, octoxynol-10, octoxynol-1, and octoxynol-12. The single-phase aqueous solution may include, for example, an amount of polyethylene oxide in a weight percentage compared to the polyethylene glycol alkylphenol ether of one of about: 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 10%, 15%, or 20%, e.g., about 3%, or a range between any two of the preceding values, e.g., about 0.1%-5%, and the like. Commercial examples of the polyethylene glycol alkylphenol ether may include, for example, TRITON™ X-102 (Dow Chemical, Midland, Mich.), LUTENSOL®, OP10 (BASF Corporation, Florham Park, N.J.), and the like.

In various embodiments, the surfactant composition may include the water-soluble polymer. The single-phase aqueous may include the water-soluble polymer in a weight percent concentration (w/w) with respect to the water of about one of: 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.25%, 0.3%, 0.35, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, e.g., 0.1%, or a range between any two of the preceding values, e.g., 0.01%-5%, 0.01%-1%, and the like.

In several embodiments, the water-soluble polymer may include one or more of a homopolymer of acrylic acid and a copolymer of acrylic acid and maleic acid. The water-soluble polymer may include one or more of: vinylpyrrolidone and vinylimidazole. Suitable commercial examples of the water-soluble polymer may include, for example, the SOKALAN® series of polymers (BTC Europe GMBH, Monheim am Rhein, Germany), for example, SOKALAN®; PA series (water-soluble homopolymers of acrylic acid). SOKALAN® CP series, e.g., CP5 (water-soluble copolymers of acrylic acid and maleic acid). SOKALAN® HP series, e.g., HP 66K (water-soluble homo- and copolymers of vinylpyrrolidone, vinylimidazole and nonionic monomers), and the like.

In some embodiments, the single phase aqueous solution may further include a chelating agent. The chelating agent may be in a weight percent concentration (w/w) with respect to the water of about one of: 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.75%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, e.g., 1%, or a range between any two of the preceding values, e.g., 0.05%-5%, and the like. The chelating agent may be polydentate. The chelating agent may include an aminopolycarboxylic acid or an alkali metal salt thereof. For example, the chelating agent may include a disodium salt of ethylene diamine tetraacetic acid. Commercial examples of the chelating agent may include, for example, TRILON® NA (BASF Corporation, Florham Park, N.J.), and the like.

In several embodiments, the single-phase aqueous solution may include the water in a weight percent concentration (w/w) of the single-phase aqueous solution of at least about one or more of: 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, and 99.5%, e.g., 95%, and the like.

In various embodiments, the single phase aqueous solution may be characterized by a pH of about one or more of 9, 9.5, 10, 10.5, 11, 11.5, and 12, or a range between any two of the preceding values, for example, between about 9 and about 12, between about 9.5 and about 11, and the like. The pH may be measured using any conventional means, such as pH paper, a pH meter (e.g., a Cole-Parmer handheld pH meter (Cole-Parmer, Vernon Hills, Ill.)), and the like.

In some embodiments, the pH may be adjusted by the addition of an acid, a base, or a buffer. For example, the pH may be adjusted by adding an amount of an alkali metal hydroxide, such as sodium hydroxide or potassium hydroxide, e.g., to provide a hydroxide concentration in millimoles per liter (mM) of about one of: 10, 20, 25, 50, 75, 100, 125, 150, 175, 191, 200, 225, 250, 275, 300, 350, 400, 450, 500, 600, 700, 800, 900, or 1000, e.g., about 191 mM, or a range between any two of the preceding values, e.g., between about 10-1000 mM, 20-500 mM, 50-400 mM, and the like. For example, the pH may be adjusted by adding an amount of the alkali metal hydroxide, e.g., sodium hydroxide, in a weight percent concentration (w/w) with respect to the water of about one of: 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.75%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, e.g., 1%, or a range between any two of the preceding values, e.g., 0.05%-5%, 0.1%-5%, and the like.

In various embodiments, the single-phase aqueous solution may consist essentially of, or may consist of, the stable peroxygen composition; the surfactant composition; and the water. The single-phase aqueous solution may consist essentially of, or may consist of, the stable peroxygen composition; the surfactant composition; the chelating agent, and the water.

In various embodiments, a process mixture is provided. The process mixture may include a post-consumer fiber. The post-consumer fiber may include a colorant. The process mixture may include a single-phase aqueous solution in contact with the post-consumer fiber. The single-phase aqueous solution may include water; a stable peroxygen composition, and a surfactant composition. The surfactant composition may include at least one of: a polyethylene glycol alkylphenol ether and a water-soluble polymer. The water-soluble polymer may include repeat units corresponding to monomers of one or more of: acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole.

In several embodiments, the colorant may include one or more of: a dye; a pigment; and a contaminant.

The post-consumer fiber may include one or more of: wool; cotton; acrylic; cellulose; sisal; jute; hemp; bamboo; an acrylic, a nylon; polyethylene terephthalate, polytrimethylene terephthalate; an olefin; blends thereof; copolymers thereof: recycled fibers thereof; and the like, e.g., nylon 6, nylon 6,6, and the like. The post-consumer fiber may be characterized by an arrangement of fibers in the form of one or more of: a woven textile, a nonwoven textile, a tufted pile, a looped pile, a patterned pile, a frieze pile, a textured pile, a multi-level pile, a cut or tip-sheared pile, a cut and loop pile, a random cut pile, a Saxony pile, a plush pile, a shag pile, a needle felt, a nonwoven portion of fiber; and the like. The post-consumer fiber may include fibers in the form of one or more of: staple fiber and bulk continuous filament. The post-consumer fiber may be derived from a carpet pile. For example, the post-consumer fiber may be a mass of nonwoven, at least partly unwound carpet pile fibers, for example, as recycled from carpet scraps or shredded carpet.

In some embodiments, the post-consumer fiber may be from a carpet e.g., including the post-consumer fiber in the form of a face yarn, e.g., carpet pile. The post-consumer fiber may be in any other form, e.g.: a rug; an upholstery; a vehicle interior, e.g., an auto headliner; a drapery material; an article of clothing; a containment material, e.g. a luggage textile or a tent textile; and the like.

In various embodiments, the post-consumer fiber may be in the form of a plurality of pieces. The plurality of pieces of the post-consumer fiber may be derived by one or more of shredding and cutting the post-consumer fiber. The post-consumer fiber, prior to shredding or cutting, may be in the form of one or more of: a tile, a roll, a remnant, a sample, an installation scrap, a deinstallation scrap reclaimed from an installed covering such as carpet removed from a building, a manufacturing scrap, and the like.

In some embodiments, the post-consumer fiber may include fibers of one or more of: wool; cotton; cellulose, such as wood fibers, sisal, jute, hemp, bamboo, synthetic cellulose (rayon), and the like; acrylics, e.g., polyacrylonitrile, polymethylmethacrylate (PMMA), and the like; nylon, e.g., nylon 6, nylon 6,6, and the like; polyester, e.g., polyethylene terephthalate (PET), polytrimethylene terephthalate (PFT, triexta (e.g., SORONA®, DuPont, Wilmington, Del.), and the like; olefin, e.g., polypropylene (PP); and the like. For example, the post-consumer fiber may include fibers of one or more of: polyethylene terephthalate, polytrimethylene terephthalate, polypropylene, nylon-6, nylon-6,6, and the like. The post-consumer fiber may also include blends, e.g., composites or mixtures of such fibers, such as an olefin/nylon blend, a wool/nylon blend, and the like. The post-consumer fiber may also include copolymers comprising any of the recited fiber polymers, e.g., modacrylic copolymers comprising polyacrylonitrile. Fibers in the post-consumer fiber may be derived from previously recycled materials, such as PET from recycled beverage containers, recycled carpet pile, and the like. Fibers in the post-consumer fiber may be in the form of staple fiber or bulk continuous filament.

In several embodiments, the post-consumer fiber may be characterized by an arrangement of fibers in the form of one or more of: a woven textile, a nonwoven textile, a tufted pile, a looped pile, a patterned pile, a frieze pile, a textured pile, a multi-level pile, a cut or tip-sheared pile, a cut and loop pile, a random cut pile, a Saxony pile, a plush pile, a shag pile, a needle felt, and the like.

The process mixture may include a decolorized portion of the post-consumer fiber. In several embodiments, the process mixture may include the water in a weight ratio to the post-consumer fiber of one or more of about: 6:1, 12:1, 18:1, 24:1, 30:1, 36:1, 42:1, or 48:1. e.g., 12:1, or a range between any two of the preceding ratios, e.g., 6:1 to 48:1, and the like.

In some embodiments, the process mixture may include the single phase aqueous solution according to any embodiment of the single phase aqueous solution described herein.

In various embodiments, a method for at least partly decolorizing post-consumer fiber using a single-phase aqueous solution is provided. The method may include providing the single phase aqueous solution. The single-phase aqueous solution may include water; a stable peroxygen composition; and a surfactant composition. The surfactant composition may include at least one of: a polyethylene glycol alkylphenol ether and a water-soluble polymer. The water-soluble polymer may include repeat units corresponding to monomers of one or more of: acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole. The method may include providing the post-consumer fiber. The post-consumer fiber may include one or more colorants. The method may include contacting the single phase aqueous solution and the post-consumer fiber to form a process mixture under conditions effective to provide a decolorized portion of the post-consumer fiber.

In some embodiments, the conditions effective to provide the decolorized portion of the post-consumer fiber comprising heating the process mixture at a temperature of about one or more of: 50° C. to 100° C.; 60° C. to 100° C.; 60° C. to 95° C.; 60° C. to 90° C.; 60° C. to 85° C.; 65° C. to 85° C.; 80° C. to 85° C.; 82° C. and the like.

In several embodiments, the conditions effective to provide the decolorized portion of the post-consumer fiber may include one or more of agitating and stirring. For example, the conditions effective to provide the decolorized portion of the post-consumer fiber may include stirring at a speed in rotations per minute of one or more of 250, 500, 750, 1000, 1250, 1500, 1750, or 2000, e.g., 1000 RPM, or a range between any two of the preceding values, e.g., 250-2000 RPM, and the like. The conditions effective to provide the decolorized portion of the post-consumer fiber may include heating and agitating for a time in hours of one or more of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 30, 36, 42, or 48, e.g., 6 hours, or a range between any two of the preceding values, e.g., 1-48 hours, 6-12 hours, and the like.

In several embodiments, the method may further include determining an initial colorant level of the post-consumer fiber; and determining a decolorized level of the colorant in the post-consumer fiber. The determining may be conducted using, for example, UV, visible, or infrared spectroscopy, for example, using standard solutions or samples for calibration as known to the art. For example, the colorant level may be analyzed with a colorimeter (e.g., a handheld WR-series colorimeter, Shenzhen Wave Optoelectronics Technology Co., Ltd., Shenzen, China) to determine L/a/b values or L/C/H values. The initial colorant level of the post-consumer fiber may be characterized, e.g., by an initial lightness L_(initial) value and the decolorized level of the colorant in the post-consumer fiber being characterized by a decolorized lightness L_(decolorized) value. L_(decolorized) may be greater than L_(initial) by a value of at least about one of: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, 30, 35, or 40. L_(decolorized) may be greater than L_(initial) by a percentage at least about one of: 102.5%, 105%, 107.5%, 110%, 112.5%, 115%, 117.5%, 120%, 125%, 130%, 135%, 140%, 145%, or 150%. See the exemplary measurements in the table in Example 5.

In some embodiments, the method may further include one or more of separating and recovering the decolorized portion of the post-consumer fiber from the process mixture. The method may further include one or more of separating and recovering at least a portion of the single phase aqueous solution from the process mixture. The method may further include one or more of separating and recovering at least a portion of the colorant from the process mixture. The method may be conducted by one or more of batch operation and continuous operation.

In some embodiments, the method may include using the single phase aqueous solution according to any embodiment of the single phase aqueous solution described herein. The method may include preparing the single phase aqueous solution according to any embodiment of the single phase aqueous solution described herein. The method may include using the process mixture according to any embodiment of the process mixture described herein. The method may include preparing the process mixture according to any embodiment of the process mixture described herein.

In various embodiments, a kit for decolorizing post-consumer fiber is provided. The kit may include a stable peroxygen composition. The kit may include a surfactant composition. The surfactant composition may include at least one of: a polyethylene glycol alkylphenol ether; and a water-soluble polymer. The water-soluble polymer may include repeat units corresponding to monomers of one or more of acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole. The kit may include instructions. The instructions may direct a user to provide the stable peroxygen composition and the surfactant composition as a single-phase aqueous solution. The instructions may direct a user to contact the single phase aqueous solution and to a post-consumer fiber comprising a colorant to form a process mixture under conditions effective to provide a decolorized portion of the post-consumer fiber.

In several embodiments, the kit may include the stable peroxygen composition or the surfactant composition as a neat composition. The kit may include a mixture of the stable peroxygen composition and the surfactant composition together with water in the form of an aqueous concentrate. The kit may include the single phase aqueous solution according to any embodiment of the single phase aqueous solution described herein. The instructions may include directing the user to prepare the single phase aqueous solution according to any embodiment of the single phase aqueous solution described herein. The instructions may include directing the user to prepare the process mixture according to any embodiment of the process mixture described herein. The instructions may direct the user to conduct any aspect of the method of decolorizing post-consumer fiber as described herein.

In various embodiments, a decolorized post-consumer fiber is provided. The decolorized post-consumer fiber may be produced according to any aspect of the method of decolorizing post-consumer fiber as described herein. For example, the decolorized post-consumer fiber of claim 52, comprising fibers of one or more of: wool; cotton; acrylic; cellulose; sisal; jute; hemp; bamboo; an acrylic, a nylon, e.g., nylon 6, nylon 6,6, and the like; polyethylene terephthalate, polytrimethylene terephthalate; an olefin; blends thereof: copolymers thereof; recycled fibers thereof; staple fiber thereof; and bulk continuous filament thereof.

Examples Example 1: Decolorization of Polyethylene Terephthalate and Polypropylene Carpet Material

To a reaction vessel equipped with a mechanical stirring blade was added 5.44 kg water, 1% (w/w) sodium percarbonate, 1% (w/w) disodium ethylene diamine tetraacetic acid, 0.2% (w/w) SOKALAN® CP5 (water-soluble acrylic acid copolymer with maleic acid, BTC Europe GMBH, Monheim am Rhein. Germany), and 0.1% (w/w) TRITON™ X-102 (Dow Chemical, Midland, Mich.) and stirred to form a single phase aqueous solution. A mass of 226 g of nonwoven, colorized post-consumer fiber from recycled carpet scrap, including polypropylene and polyethylene terephthalate fibers, was added to the single phase aqueous solution. The resulting process mixture was heated to about 82° C. and stirred at about 1000 RPM for 12 h. The post-consumer fiber, initially a dark tan in color, was decolorized to a light beige. The decolorized PET and PP carpet fibers were removed from the process mixture by filtration.

Example 1: Decolorization of Nylon Carpet Material Carpet Material

To a reaction vessel equipped with a mechanical stirring blade was added 5.44 kg water, 1% (w/w) sodium percarbonate, 1% (w/w) disodium ethylene diamine tetraacetic acid, 0.2% (w/w) SOKALAN® CP5 (water-soluble acrylic acid copolymer with maleic acid. BTC Europe GMBH, Monheim am Rhein, Germany), and 0.1% (w/w) TRITON™ X-102 (Dow Chemical, Midland, Mich.) and stirred to form a single phase aqueous solution. A mass of 226 g of nonwoven, colorized post-consumer fiber from recycled carpet scrap, including nylon 6.6 fibers, was added to the single phase aqueous solution. The pH was measured to be about 11 using a Cole-Parmer handheld pH meter (Cole-Parmer, Vernon Hills, Ill.). The resulting process mixture was heated to about 82° C. and stirred at about 1000 RPM for 12 h. The decolorized post-consumer nylon 6.6 carpet fibers were removed from the process mixture by filtration. The post-consumer fiber, initially a dark tan in color, was decolorized to a light beige. The extent of decolorization is characterized in Example 5.

Example 2: Decolorization of Nylon Carpet Material Carpet Material

To a reaction vessel equipped with a mechanical stirring blade was added 5.44 kg water, 1% (w/w) sodium percarbonate, and 0.2% (w/w) SOKALAN® HP 66K (water-soluble homo- and copolymers of vinylpyrrolidone, vinylimidazole and nonionic monomers, BTC Europe GMBH. Monheim am Rhein, Germany), and stirred to form a single phase aqueous solution. A mass of 226 g of nonwoven, colorized post-consumer fiber from recycled carpet scrap, including nylon 6,6 fibers, was added to the single phase aqueous solution. The pH was measured to be about 10.5 using a Cole-Parmer handheld pH meter (Cole-Parmer, Vernon Hills, Ill.). The resulting process mixture was heated to about 82° C. and stirred at about 1000 RPM for 12 h. The decolorized post-consumer nylon 6,6 carpet fibers were removed from the process mixture by filtration. The post-consumer fiber, initially a dark tan in color, was decolorized to a medium pink. The extent of decolorization is characterized in Example 5.

Example 3: Decolorization of Nylon Carpet Material Carpet Material

To a reaction vessel equipped with a mechanical stirring blade was added 5.44 kg water, 1% (w/w) sodium percarbonate, 0.1% (w/w) LUTENSOL® OP10 (BASF Corporation, Florham Park, N.J.), and stirred to form a single phase aqueous solution. A mass of 226 g of nonwoven, colorized post-consumer fiber from recycled carpet scrap, including nylon 6,6 fibers, was added to the single phase aqueous solution. The pH was measured to be about 9.2 using a Cole-Parmer handheld pH meter (Cole-Parmer, Vernon Hills, Ill.). The resulting process mixture was heated to about 82° C. and stirred at about 1000 RPM for 12 h. The decolorized post-consumer nylon 6,6 carpet fibers were removed from the process mixture by filtration. The post-consumer fiber, initially a dark tan in color, was decolorized to a light beige. The extent of decolorization is characterized in Example 5.

Example 4: Decolorization of Nylon Carpet Material Carpet Material

To a reaction vessel equipped with a mechanical stirring blade was added 5.44 kg water, 1% (w/w) sodium percarbonate, 0.2% (w/w) SOKALAN® HP 66K (water-soluble homo- and copolymers of vinylpyrrolidone, vinylimidazole and nonionic monomers, BTC Europe GMBH, Monheim am Rhein, Germany), and 0.1% (w/w) TRITON™ X-102 (Dow Chemical, Midland, Mich.) and stirred to form a single phase aqueous solution. A mass of 226 g of nonwoven, colorized post-consumer fiber from recycled carpet scrap, including nylon 6,6, was added to the single phase aqueous solution. The pH was measured to be about 11 using a Cole-Parmer handheld pH meter (Cole-Parmer, Vernon Hills, Ill.). The resulting process mixture was heated to about 82° C. and stirred at about 1000 RPM for 12 h. The decolorized post-consumer nylon 6.6 carpet fibers were removed from the process mixture by filtration. The post-consumer fiber, initially a dark tan in color, was decolorized to a medium pink. The extent of decolorization is characterized in Example 5.

Example 5: Decolorization Results Characterization of Nylon Carpet Material

A colorimetric analysis was performed for the raw material (the nonwoven, colorized post-consumer fiber from recycled carpet scrap, including nylon 6,6 fibers), as well as the decolorized nylon carpet fibers obtained from Examples 1-4 (rinsed with water and dried). The samples analyzed with a handheld WR-series colorimeter (Shenzhen Wave Optoelectronics Technology Co., Ltd., Shenzen, China) to determine L/a/b values. Table 1 shows the colorimeter results for the raw material and the decolorized nylon carpet fibers obtained from Examples 1-4.

TABLE 1 L ΔL % L a b Raw material 56.71 — — 2.89 10.54 Example 1 60.66 3.95 107% 3.24 7.36 Example 3 63.86 7.15 113% 2.82 6.7 Example 2 68.56 11.85 121% 6.15 12.1 Example 4 71 14.29 125% 4.59 7.49

As shown in Table 1, the value of L increased substantially for each of Examples 1-4, demonstrating significant decolorization. Additionally, further scoping trials were undertaken using nonwoven, colorized post-consumer fiber from recycled carpet scrap, including polyethylene terephthalate carpet material. The results obtained were substantially similar to the preceding results obtained with nylon.

To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. See Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean “on” or “onto.” To the extent that the term “selectively” is used in the specification or the claims, it is intended to refer to a condition of a component wherein a user of the apparatus may activate or deactivate the feature or function of the component as is necessary or desired in use of the apparatus. To the extent that the terms “operatively coupled” or “operatively connected” are used in the specification or the claims, it is intended to mean that the identified components are connected in a way to perform a designated function. To the extent that the term “substantially” is used in the specification or the claims, it is intended to mean that the identified components have the relation or qualities indicated with degree of error as would be acceptable in the subject industry.

As used in the specification and the claims, the singular forms “a,” “an,” and “the” include the plural unless the singular is expressly specified. For example, reference to “a compound” may include a mixture of two or more compounds, as well as a single compound.

As used herein, the term “about” in conjunction with a number is intended to include±10% of the number. In other words, “about 10” may mean from 9 to 11.

As used herein, the terms “optional” and “optionally” mean that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not.

As stated above, while the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art, having the benefit of the present application. Therefore, the application, in its broader aspects, is not limited to the specific details, illustrative examples shown, or any apparatus referred to. Departures may be made from such details, examples, and apparatuses without departing from the spirit or scope of the general inventive concept.

As used herein, “substituted” refers to an organic group as defined below (e.g., an alkyl group) in which one or more bonds to a hydrogen atom contained therein may be replaced by a bond to non-hydrogen or non-carbon atoms. Substituted groups also include groups in which one or more bonds to a carbon(s) or hydrogen(s) atom may be replaced by one or more bonds, including double or triple bonds, to a heteroatom. A substituted group may be substituted with one or more substituents, unless otherwise specified. In some embodiments, a substituted group may be substituted with 1, 2, 3, 4, 5, or 6 substituents. Examples of substituent groups include: halogens (i.e., F, Cl, Br, and I); hydroxyls; alkoxy, alkenoxy, aryloxy, aralkyloxy, heterocyclyloxy, and heterocyclylalkoxy groups; carbonyls (oxo); carboxyls; esters; urethanes; oximes; hydroxylamines; alkoxyamines; aralkoxyamines; thiols; sulfides; sulfoxides; sulfones; sulfonyls; sulfonamides; amines; N-oxides; hydrazines; hydrazides; hydrazones; azides; amides; ureas; amidines; guanidines; enamines; imides; isocyanates; isothiocyanates; cyanates; thiocyanates; imines; nitro groups; or nitriles (i.e., CN). A “per”-substituted compound or group is a compound or group having all or substantially all substitutable positions substituted with the indicated substituent. For example, 1,6-diiodo perfluoro hexane indicates a compound of formula C₆F₁₂I₂, where all the substitutable hydrogens have been replaced with fluorine atoms.

Substituted ring groups such as substituted cycloalkyl, aryl, heterocyclyl and heteroaryl groups also include rings and ring systems in which a bond to a hydrogen atom may be replaced with a bond to a carbon atom. Substituted cycloalkyl, aryl, heterocyclyl and heteroaryl groups may also be substituted with substituted or unsubstituted alkyl, alkenyl, and alkynyl groups as defined below.

Alkyl groups include straight chain and branched chain alkyl groups having from 1 to 12 carbon atoms, and typically from 1 to 10 carbons or, in some examples, from 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Examples of straight chain alkyl groups include groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Examples of branched alkyl groups include, but are not limited to, isopropyl, iso-butyl, sec-butyl, tert-butyl, neopentyl, isopentyl, and 2,2-dimethylpropyl groups. Representative substituted alkyl groups may be substituted one or more times with substituents such as those listed above and include, without limitation, haloalkyl (e.g., trifluoromethyl), hydroxyalkyl, thioalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, or carboxyalkyl.

Cycloalkyl groups include mono-, bi- or tricyclic alkyl groups having from 3 to 12 carbon atoms in the ring(s), or, in some embodiments, 3 to 10, 3 to 8, or 3 to 4, 5, or 6 carbon atoms. Exemplary monocyclic cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. In some embodiments, the cycloalkyl group has 3 to 8 ring members, whereas in other embodiments, the number of ring carbon atoms ranges from 3 to 5, 3 to 6, or 3 to 7. Bi- and tricyclic ring systems include both bridged cycloalkyl groups and fused rings, such as, but not limited to, bicyclo[2.1.1]hexane, adamantyl, or decalinyl. Substituted cycloalkyl groups may be substituted one or more times with non-hydrogen and non-carbon groups as defined above. However, substituted cycloalkyl groups also include rings that may be substituted with straight or branched chain alkyl groups as defined above. Representative substituted cycloalkyl groups may be mono-substituted or substituted more than once, such as, but not limited to, 2,2-, 2,3-, 2,4-2,5- or 2,6-disubstituted cyclohexyl groups, which may be substituted with substituents such as those listed above.

Aryl groups may be cyclic aromatic hydrocarbons that do not contain heteroatoms. Aryl groups herein include monocyclic, bicyclic and tricyclic ring systems. Aryl groups include, but are not limited to, phenyl, azulenyl, heptalenyl, biphenyl, fluorenyl, phenanthrenyl, anthracenyl, indenyl, indanyl, pentalenyl, and naphthyl groups. In some embodiments, aryl groups contain 6-14 carbons, and in others from 6 to 12 or even 6-10 carbon atoms in the ring portions of the groups. In some embodiments, the aryl groups may be phenyl or naphthyl. Although the phrase “aryl groups” may include groups containing fused rings, such as fused aromatic-aliphatic ring systems (e.g., indanyl or tetrahydronaphthyl), “aryl groups” does not include aryl groups that have other groups, such as alkyl or halo groups, bonded to one of the ring members. Rather, groups such as tolyl may be referred to as substituted aryl groups. Representative substituted aryl groups may be mono-substituted or substituted more than once. For example, monosubstituted aryl groups include, but are not limited to, 2-, 3-, 4-, 5-, or 6-substituted phenyl or naphthyl, which may be substituted with substituents such as those above.

Aralkyl groups may be alkyl groups as defined above in which a hydrogen or carbon bond of an alkyl group may be replaced with a bond to an aryl group as defined above. In some embodiments, aralkyl groups contain 7 to 16 carbon atoms, 7 to 14 carbon atoms, or 7 to 10 carbon atoms. Substituted aralkyl groups may be substituted at the alkyl, the aryl or both the alkyl and aryl portions of the group. Representative aralkyl groups include but are not limited to benzyl and phenethyl groups and fused (cycloalkylaryl)alkyl groups such as 4-indanylethyl. Substituted aralkyls may be substituted one or more times with substituents as listed above.

Groups described herein having two or more points of attachment (i.e., divalent, trivalent, or polyvalent) within the compound of the technology may be designated by use of the suffix, “ene.” For example, divalent alkyl groups may be alkylene groups, divalent aryl groups may be arylene groups, divalent heteroaryl groups may be heteroarylene groups, and so forth. In particular, certain polymers may be described by use of the suffix “ene” in conjunction with a term describing the polymer repeat unit.

Alkoxy groups may be hydroxyl groups (—OH) in which the bond to the hydrogen atom may be replaced by a bond to a carbon atom of a substituted or unsubstituted alkyl group as defined above. Examples of linear alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, butoxy, pentoxy, or hexoxy. Examples of branched alkoxy groups include, but are not limited to, isopropoxy, sec-butoxy, tert-butoxy, isopentoxy, or isohexoxy. Examples of cycloalkoxy groups include, but are not limited to, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, or cyclohexyloxy. Representative substituted alkoxy groups may be substituted one or more times with substituents such as those listed above.

The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims. 

1. A single-phase aqueous solution for at least partly decolorizing post-consumer fiber, the single-phase aqueous solution comprising: water in a weight percent concentration (w/w) of the single-phase aqueous solution of at least about one or more of: 92%; a stable peroxygen composition; and a surfactant composition comprising at least one of: a polyethylene glycol alkylphenol ether; and a water-soluble polymer comprising repeat units corresponding to monomers of one or more of acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole.
 2. The single-phase aqueous solution of claim 1, the stable peroxygen composition comprising an alkali metal salt of one or more of: peroxide, percarbonate, persulfate, or perborate.
 3. The single-phase aqueous solution of claim 1, the stable peroxygen composition being present in an amount effective to provide: a peroxide concentration in millimoles per liter (mM) of about one of: 10, 20, 25, 50, 75, 100, 125, 150, 175, 191, 200, 225, 250, 275, 300, 350, 400, 450, 500, 600, 700, 800, 900, or 1000, or a range between any two of the preceding values; or sodium percarbonate in a weight percent concentration (w/w) with respect to the water of about one of: 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.75%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, or a range between any two of the preceding values.
 4. The single-phase aqueous solution of claim 1, comprising the polyethylene glycol alkylphenol ether in a weight percent concentration (w/w) with respect to the water of about one of: 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.25%, 0.3%, 0.35, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, or a range between any two of the preceding values.
 5. The single-phase aqueous solution of claim 1, the polyethylene glycol alkylphenol ether characterized by an average number of ethylene oxide repeat units of one of about: 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, or a range between any two of the preceding values.
 6. The single-phase aqueous solution of claim 1, an alkyl group of the polyethylene glycol alkylphenol ether being a C₄-C₁₆, branched or unbranched alkyl group; or the polyethylene glycol alkylphenol ether being represented by the following formula, wherein n is an average number of repeat units from about 9 to about 14:


7. The single-phase aqueous solution of claim 1, the polyethylene glycol alkylphenol ether comprising one or more of: octoxynol-9, octoxynol-10, octoxynol-11, and octoxynol-12.
 8. The single-phase aqueous solution of claim 1, further comprising an amount of polyethylene oxide in a weight percentage compared to the polyethylene glycol alkylphenol ether of one of about: 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 10%, 15%, or 20%, or a range between any two of the preceding values.
 9. The single-phase aqueous solution of claim 1, comprising the water-soluble polymer in a weight percent concentration (w/w) with respect to the water of about one of: 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.25%, 0.3%, 0.35, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, or a range between any two of the preceding values.
 10. The single-phase aqueous solution of claim 1, the water-soluble polymer comprising: one or more of a homopolymer of acrylic acid and a copolymer of acrylic acid and maleic acid; or one or more of: vinylpyrrolidone and vinylimidazole.
 11. The single-phase aqueous solution of claim 1, further comprising a chelating agent wherein the chelating agent is polydentate; or the chelating agent comprises an aminopolycarboxylic acid or an alkali metal salt thereof; or the chelating agent comprises a disodium salt of ethylene diamine tetraacetic acid; and the chelating agent in a weight percent concentration (w/w) with respect to the water of about one of: 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.75%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, or a range between any two of the preceding values.
 12. A process mixture, comprising: a post-consumer fiber, the post-consumer fiber comprising a colorant that is one or more of: a dye; a pigment; and a contaminant; and a single-phase aqueous solution in contact with the post-consumer fiber, the single phase aqueous solution comprising: water in a weight percent concentration (w/w) of the single-phase aqueous solution of at least about 92%; a stable peroxygen composition; and a surfactant composition comprising at least one of: a polyethylene glycol alkylphenol ether; and a water-soluble polymer comprising repeat units corresponding to monomers of one or more of acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole.
 13. The process mixture of claim 12, the post-consumer fiber comprising one or more of: wool; cotton; acrylic; cellulose; sisal; jute; hemp; bamboo; an acrylic, a nylon; polyethylene terephthalate, polytrimethylene terephthalate; an olefin; blends thereof; copolymers thereof; and recycled fibers thereof; or the post-consumer fiber comprising fibers in the form of one or more of: staple fiber and bulk continuous filament; or the post-consumer fiber being derived from a carpet pile.
 14. The process mixture of claim 12, the post-consumer fiber characterized by an arrangement of fibers in the form of one or more of: a woven textile, a nonwoven textile, a tufted pile, a looped pile, a patterned pile, a frieze pile, a textured pile, a multi-level pile, a cut or tip-sheared pile, a cut and loop pile, a random cut pile, a Saxony pile, a plush pile, a shag pile, a needle felt, and a nonwoven portion of fiber.
 15. The process mixture of claim 12, comprising the water in a weight ratio to the post-consumer fiber of one or more of about: 6:1, 12:1, 18:1, 24:1, 30:1, 36:1, 42:1, or 48:1, or a range between any two of the preceding ratios.
 16. A method for at least partly decolorizing post-consumer fiber using a single-phase aqueous solution, comprising: providing the single phase aqueous solution comprising: water; a stable peroxygen composition; and a surfactant composition comprising at least one of: a polyethylene glycol alkylphenol ether; and a water-soluble polymer comprising repeat units corresponding to monomers of one or more of acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole; providing the post-consumer fiber comprising one or more colorants; and contacting the single phase aqueous solution and the post-consumer fiber to form a process mixture under conditions effective to provide a decolorized portion of the post-consumer fiber.
 17. The method of claim 16, the conditions effective to provide the decolorized portion of the post-consumer fiber comprising: heating the process mixture at a temperature of about one or more of: 50° C. to 100° C.; 60° C. to 100° C.; 60° C. to 95° C.; 60° C. to 90° C.; 60° C. to 85° C.; 65° C. to 85° C.; 80° C. to 85° C.; and 82° C.; or one or more of agitating and stirring; or comprising heating and agitating for a time in hours of one or more of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 30, 36, 42, or 48, or a range between any two of the preceding values.
 18. The method of claim 16, comprising: determining an initial colorant level of the post-consumer fiber and the initial colorant level of the post-consumer fiber being characterized by an L_(initial) value; and determining a decolorized level of the colorant in the post-consumer fiber, the decolorized level of the colorant in the post-consumer fiber being characterized by an L_(decolorized) value, L_(decolorized) being greater than L_(initial) by one or more of: a value of at least about one of: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, 30, 35, or 40; or a percentage at least about one of: 102.5%, 105%, 107.5%, 110%, 112.5%, 115%, 117.5%, 120%, 125%, 130%, 135%, 140%, 145%, or 150%.
 19. The method of claim 16, further comprising: one or more of separating and recovering at least a portion of the colorant from the process mixture; or comprising conducting the method via one or more of: batch operation and continuous operation.
 20. A kit for decolorizing post-consumer fiber, comprising: a stable peroxygen composition; a surfactant composition comprising at least one of: a polyethylene glycol alkylphenol ether; and a water-soluble polymer comprising repeat units corresponding to monomers of one or more of acrylic acid, maleic acid, vinylpyrrolidone, and vinylimidazole; instructions, the instructions directing a user to: provide the stable peroxygen composition and the surfactant composition as a single-phase aqueous solution; and contact the single phase aqueous solution and to a post-consumer fiber comprising a colorant to form a process mixture under conditions effective to provide a decolorized portion of the post-consumer fiber. 